A test is not a unit test if:
It talks to the database
It communicates across the network
It touches the file system
It can't run at the same time as any of your other unit tests
You have to do special things to your environment (such as editing config files) to run it.
Pilot project in Stockholm - photo radar cameras measure speed of passing cars. Those above the speed limit receive a fine. Those below are entered into a lottery for a chance to win a portion of the fines from speeders (up to $3000). Average speeds fell from 32km/h to 25 km/h.